<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div,span{
            width: 100px;
            height: 100px;
            border: 1px solid black;
            margin-top: 10px;
        }
        /* [class]{ 
            background-color: blanchedalmond;
        }
        div[class=box1]{
            background-color: blanchedalmond;
        }
        div[class]{
            background-color: blanchedalmond;
        } */
       .box ~div{
           background-color: blanchedalmond;
       }
        
    </style>
</head>
<body>
    <div class="box">
        <div class="box1"></div>
        <div class="box2"></div>
        <span class="box3">9999999999</span>
        <div></div>
    </div>
    
</body>
</html>